OK, new thread. This is an important subject but nothing to do with graph theory.
On Thu, Jan 19, 2012 at 12:34 PM, Bill Page wrote: > One could easily argue that the difference between Cross and Record is > "just a convention" too but Aldor implements both, SPAD only Record. > On the contrary I consider Rep (the concept, not the specific name) an > essential part of the SPAD language. Without it writing computer > algebra code would be more awkward. Consider Sage for example. On Thu, Jan 19, 2012 at 12:50 PM, Ralf Hemmecke wrote: > On 01/19/2012 06:34 PM, Bill Page wrote: >> >> One could easily argue that the difference between Cross and Record is >> "just a convention" too but Aldor implements both, > > > Record is mutable, Cross is not. > Yes, that is my point. We can treat many things as convention, including mutability. The question is this somehow essential to the language? On Thu, Jan 19, 2012 at 12:56 PM, Ralf Hemmecke wrote: > The grammar for capsules (section 13.2) clearly distinguishes assignment > to the special variable Rep. > > and all Spad compilers reflect that. > > But that doesn't answer all of my questions. It only says what the current > compiler does, but not whether Rep must be part of the *language*. > As you know there is no definition of the SPAD language besides the descriptions in Axiom book, the code in Axiom (and FriCAS and OpenAxiom) libraries as examples and the compilers in terms of what they currently allow. So this is not a "language lawyer" issue. Clearly also all of these languages are computation universal in the sense that one can be translated into another. The issue for me is how suitable is the "language" for the purpose for which it is used. It seems very hard to define this in other than a subjective way and I suppose that therefore we might never totally agree. To some extent it is just a matter of preference. Still some things do seem to work much better than others. No? So just to be clear: Are you suggesting that Rep is not an essential part of the SPAD language? Regards, Bill Page. -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/fricas-devel?hl=en.
